Film forming apparatus, manufacturing management system and method of manufacturing semiconductor devices

ABSTRACT

A film forming apparatus which forms a film on a substrate by utilizing a chemical solution, including: 
     a correlation data creating unit which creates a correlation data that is related to the quality of a chemical solution, from data that is related to the properties of the chemical solution including at least one of data on storage temperature for the chemical solution to be loaded and data on pressure applied to the chemical solution to be loaded; and 
     a determining unit which determines whether or not the chemical solution holds expected quality thereof on the bases of the correlation data.

CROSS REFERENCE TO RELATED APPLICATION

This application claims benefit of priority under 35USC §119 to JapanesePatent Application No. 2004-138378, filed on May 7, 2004, the contentsof which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a film forming apparatuses, amanufacturing management system, and a method of manufacturingsemiconductor devices.

2. Related Background Art

In manufacturing of devices, the formation of a film, such as a SOG(Spin on Glass) film as an insulating layer, an antireflection film usedin lithography processes, and a photoresist film, using a chemicalsolution is being employed in many processes. Most of these chemicalsolutions deteriorate as time passes; therefore, in general, in order tomaintain predetermined performances, or in some cases, in order toensure safety in manufacturing, manufacturers of such chemical solutionsset chemical-solution storage conditions and quality assurance periods.

In the case where the amount of a chemical solution to be used is largeenough compared to the capacity of the container of the chemicalsolution, and where the entire chemical solution in one container isquickly consumed, it is very seldom that the quality assurance period ofthe chemical solution raises a problem. However, in the case wheredevices to be manufactured are a wide variety of products in smallquantities, whereby the amounts of chemical solutions to be used arelittle, where the production line for the devices are halted for somereasons, or where any event occurs that halts for a long time processingin film forming processes for the devices, the quality assurance periodsof the chemical solutions may expire.

In order to address the foregoing case, when chemical solutions areutilized in film forming apparatuses, the chemical solutions arereplaced based on their quality assurance periods. Specifically, amethod has been put into practical use in which sequential check isimplemented in a periodical and manual way whether or not qualityassurance periods have expired, and so has been a quality managementsystem that receives by means of bar codes or the like data on amanufacturing date at the timing when a chemical solution is loaded in acoating system and that issues a warning when the quality assuranceperiod expires.

Among the foregoing problems, the cases where a chemical-solutioncontainer is kept being connected with a manufacturing system regardlessof the expiration of the quality assurance period include the followingtwo cases: In the first place, relying on a periodical and manual checkmay cause chemical solutions whose quality assurance periods haveexpired to be kept being loaded, by a worker's false recognition or byfalse instructions. In the second place, even when a warning of theexpiration of a quality assurance period has been issued by means of barcodes, a worker makes a false recognition.

In addition, even though the quality assurance period of a chemicalsolution in a chemical-solution container has not expired, the qualityassurance period of the chemical solution remaining in the pipelinewithin a film forming apparatus may have expired. Even though such arule is adopted in which, after the replacement of the chemical-solutioncontainer, the entire chemical solution in the pipeline is disposed of,the false recognition by a worker may make the disposal insufficient.

As discussed above, existing technology may cause the possibility ofutilizing chemical solutions whose quality assurance periods haveexpired.

Moreover, even when quality assurance periods are still valid, ifstorage conditions for chemical solutions, in particular, temperaturemanagement conditions, from manufacturing of the chemical solutions toloading them in a film forming apparatus are inappropriate, thedeterioration of the chemical solutions develops. Therefore, a caseexists in which management by means of a quality assurance period onlyis insufficient.

Still moreover, even though temperature management during the time frommanufacturing of a chemical solution to loading it in a film formingapparatus is appropriate, if the temperature of the pipeline within thefilm forming apparatus is inappropriate, the deterioration of thechemical solutions develops in the pipeline, even when the qualityassurance period of the chemical solution has not expired. For example,this corresponds to a case where a pipeline within a film formingapparatus is being left at room temperature, while the storageconditions for chemical solutions include low temperature.

Meanwhile, when a chemical solution to be utilized is very expensive,the reduction of its amount to be used is effective to reduction of costin manufacturing devices. In general, manufacturers of chemicalsolutions offer quality assurance periods for chemical solutions to beprovided, while anticipating a certain extent of safety factors.Accordingly, managing by means of a quality assurance period only maycause chemical solutions that are still usable to be disposed of.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda film forming apparatus which forms a film on a substrate by utilizinga chemical solution, comprising:

a correlation data creating unit which creates a correlation data thatis related to the quality of a chemical solution, from data that isrelated to the properties of the chemical solution including at leastone of data on storage temperature for the chemical solution to beloaded and data on pressure applied to the chemical solution to beloaded; and

a determining unit which determines whether or not the chemical solutionholds expected quality thereof on the bases of the correlation data.

According to a second aspect of the present invention, there is provideda method of manufacturing semiconductor devices, comprising a method offorming a film on a substrate, said method of forming a film including:

creating a correlation data that is related to the quality of a chemicalsolution from data that is related to the properties of the chemicalsolution including at least one of data on storage temperature for thechemical solution to be loaded and data on pressure applied to thechemical solution to be loaded; and

determining whether or not the chemical solution holds expected qualitythereof on the bases of the correlation data.

According to a third aspect of the present invention, there is provideda manufacturing management system which allocates product lots to aplurality of external film forming apparatuses which forms films onsubstrates by utilizing chemical solutions, said film formingapparatuses each comprising a correlation data creating unit whichcreates correlation data that is related to the quality of a chemicalsolution from data that is related to the properties of the chemicalsolution including at least one of data on storage temperature for thechemical solution to be loaded therein and data on pressure applied tothe chemical solution to be loaded therein, and a determining unit whichdetermines on the basis of the correlation data whether or not thechemical solution holds expected quality thereof; said manufacturingmanagement system determines for each of the external film formingapparatuses a margin of the chemical solution for the expected quality,based on a result of determination by the determining unit of theexternal film forming apparatus exterior thereto, and then decidespriorities among the film forming apparatuses, based on the results ofdetermination on the margins; and

wherein the allocation is implemented by the decided priorities.

According to a fourth aspect of the present invention, there is provideda manufacturing management system connectable to a plurality of externalfilm forming apparatuses which forms films on substrates by utilizingchemical solutions, said film forming apparatuses each comprising acorrelation data creating unit which creates correlation data that isrelated to the quality of a chemical solution from data that is relatedto the properties of the chemical solution including at least one ofdata on storage temperature for the chemical solution to be loadedtherein and data on pressure applied to the chemical solution to beloaded therein, and a determining unit which determines whether or notthe chemical solution holds expected quality thereof on the basis of thecorrelation data; said manufacturing management system determining foreach of the film forming apparatuses a margin of the chemical solutionfor the expected quality on the basis of a result of determination bythe determining unit of said film forming apparatus, deciding prioritiesamong the film forming apparatuses on the basis of the results ofdetermination on the margins, and allocating respective product lots tothe film forming apparatuses based on the decided priorities.

According to a fifth aspect of the present invention, there is provideda manufacturing management system connectable to an external filmforming apparatus which forms a film on a substrate by utilizing achemical solution, said film forming apparatus comprising a detectingunit which detects correlation data that is related to the quality of achemical solution from data that is related to the properties of thechemical solution including at least one of data on storage temperaturefor the chemical solution to be loaded therein and data on pressureapplied to the chemical solution to be loaded therein, saidmanufacturing management system comprising a determining unit whichdetermines whether or not the chemical solution holds expected qualitythereof on the basis of the correlation data received from said externalfilm forming apparatus, and a commanding unit which creates a signal tourge replacement of the chemical solution in response to determinationof the determining unit to supply the external film forming apparatuswith the signal.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings,

FIG. 1 is a block diagram illustrating the schematic configuration of afilm forming apparatus according to Embodiment 1 of the presentinvention;

FIG. 2 is a blockchart showing an example of a film forming procedure,as a comparative example, based on conventional technology;

FIG. 3 is a graph, with storage temperature as a parameter, representingan example of a correlation between the number of days that have elapsedsince the manufacturing of chemical solutions and characteristic valuesof photoresist;

FIG. 4 is a blockchart showing an example of the operating procedure ofthe film forming apparatus illustrated in FIG. 1;

FIG. 5 is a blockchart showing the schematic procedure of Embodiment 2of the present invention;

FIG. 6 is a block diagram illustrating the schematic configuration of afilm forming apparatus according to Embodiment 3 of the presentinvention;

FIG. 7 is a blockchart showing an example of the operating procedure ofthe film forming apparatus illustrated in FIG. 6;

FIG. 8 is a block diagram illustrating principal parts of a film formingapparatus according to Embodiment 5 of the present invention;

FIG. 9 is a blockchart showing the schematic procedure of Embodiment 5of the present invention; and

FIG. 10 is a block diagram illustrating a manufacturing managementsystem and a film forming apparatus connected thereto, according toEmbodiment 7 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be discussed, referring to thedrawings. Hereinafter, the discussion will be made by dealing with as anexample a case where a photoresist film that is utilized in alithography process of a semiconductor-device manufacturing process isformed, or in which a SOG film that is utilized as part of amultilayered antireflection film is formed. In addition, in each ofdrawings below, the same parts are indicated with the same referencenumbers and duplicate descriptions for the same parts are implementedonly if necessary.

(1) Film Forming Apparatus According to Embodiment 1

FIG. 1 is a block diagram illustrating the schematic configuration of afilm forming apparatus according to Embodiment 1. A film formingapparatus 2 illustrated in FIG. 2 is provided with an input device 22, amemory MR1, a calculating unit 14, a determining unit 12, and awarning-signal generating unit 16. The input device 22 inputs atemperature history of a chemical solution to be utilized for forming afilm or predetermined calculation parameters for calculation. Thetemperature history of a chemical solution, in Embodiment 1, forexample, corresponds to data related to properties of the chemicalsolution. The memory MR1 stores the temperature history inputted, thecalculation parameters inputted, and threshold-value informationdescribed later. In addition, as described later, the calculating unit14 may in some cases calculate a threshold value by utilizing data inthe memory MR1. The memory MR1 can also store in the form of a recipefile a series procedure of film forming methods described later. InEmbodiment 1, the calculating unit 14, for example, corresponds tocorrelation data creating means, reads out the temperature history dataand the calculation parameters from the memory MR1, and then implementspredetermined calculation processing. The calculated result, forexample, corresponds to correlation data. The determining unit 12 readsout the threshold-value information from the memory MR1, and, bycomparing the calculation result calculated by the calculating unit 14with the foregoing threshold value, determines that the chemicalsolution to be utilized has desired ability in terms of predeterminedproperties, thereby outputting a determined result. If the calculationresult is false, after receiving the determined result, thewarning-signal generating unit 16 generates and outputs a warning signalthat urges the worker to replace the chemical solution in apredetermined container or the chemical solution in a predeterminedzone.

(2) Comparative Example

Before discussing the operation of the film forming apparatus 2illustrated in FIG. 1, a comparative example with regard to Embodiment 1will be referred to. The blockchart in FIG. 2 shows the outline of achemical-solution management procedure in the case where photoresistsolution used in a lithography process of a semiconductor-device formingprocess is utilized in a prior-art film forming apparatus.

The photoresist solution has a quality assurance period, underpredetermined storage conditions, that is set by a photoresist-solutionmanufacturer and that begins from its manufacturing date. For example,the quality assurance period is six months at room temperature, and, foranother example, it is three months at 5° C. (Blocks B2 and B92).

The carried container for the photoresist solution is loaded in aphotoresist coating/developing system (Blocks B4 and B6), and then theuse of the photoresist solution is started (Block B94). In the loadingof the container, the quality assurance period being written on thechemical-solution container is recorded in a predetermined recordingpaper (Block B10). In the case where a quality management systemutilizing bar codes or the like is employed, the quality assuranceperiod is inputted according to a predetermined method.

By periodically checking the recording paper and the chemical-solutioncontainers, whether or not the quality assurance periods of the chemicalsolutions have expired is sequentially ascertained (Block 96). After theascertainment, if the quality assurance period has expired, thechemical-solution container is replaced by another container whosequality assurance period has not expired (Blocks B98 and B6). In thissituation, in the case where a quality management system utilizing barcodes or the like is employed, a warning is issued to the worker (Block34). In addition, it is preferable that not only the container isreplaced, but also the chemical solution, within the pipeline in thefilm forming apparatus, whose quality assurance period has expired, isdisposed of and is replaced by a new chemical solution.

Many types of chemical solutions are generally replaced before theirquality assurance periods expire; however, in the case where the amountof a chemical solution to be used is little, in the case where aperiodical check is underestimated, or in other cases, a chemicalsolution whose quality assurance period has expired is kept beingloaded, whereby a performance-deteriorated photoresist film is formed,thereby resulting in reimplementing of a lithography process or a defectin manufacturing.

(3) Processing Procedure in Embodiment 1

Next, the operation of the film forming apparatus 2 illustrated in FIG.1 will be discussed, referring to FIGS. 3 and 4.

In the present embodiment, the discussion will be made by dealing with acase where a chemical solution for forming a film is utilized whilebeing contained in a deformable container. By applying pressure to sucha container, the chemical solution in the container is pushed outwithout contacting with the pressurized gas.

In the first place, as a procedure of preprocessing, with regard topredetermined properties, of a photoresist solution utilized for forminga target photoresist film, that deteriorates with time, by preliminarilyobtaining data for storage temperature and elapse of time, conditionsunder which the predetermined properties can not be satisfied arecalculated in advance. In FIG. 3 is represented an example of thecorrelation, with storage temperatures as a parameter, between thenumber of days that have elapsed from the manufacturing date of thechemical solution and characteristic values of photoresist films. In theproperties represented in FIG. 3, in the case where the storagecondition for the chemical solution is room temperature, for example, inthe low 20s° C. in the case of a clean room for semiconductor devicemanufacture, the entire temperature history beginning from themanufacturing date is important. In contrast, as can be seen in theproperties represented in FIG. 3, in the case where the condition forstorage and carriage from manufacturing to loading of the chemicalsolution in a film forming apparatus is −10° C., the number of days thathave elapsed during the storage very little affects the predeterminedproperties of the solution; therefore, the number of days that haveelapsed during the storage can substantially be neglected, but if aduration exists in which the storage temperature exceeds −10° C. duringcarriage of a chemical solution, during storage of a chemical solution,or after the loading of the chemical solution in the film formingapparatus, the temperature history during the duration is important.

The properties, of the photoresist solution, that deteriorate with timeinclude, for example, other than exposure sensitivity of a predeterminedpattern under predetermined exposure conditions, change in a photoresistshape under predetermined exposure conditions (one or more types ofinformation on critical dimension of pattern measured with apredetermined method and sidewall angles), the number of defects infilm-forming, and the number of defects after development.

Next, as shown in FIG. 4, a manufactured and carried chemical-solutioncontainer (Blocks B2 and B4) is loaded in a film forming apparatus(Block B6). While the chemical solution is in a standby state after thecontainer has been loaded (Block B8), with regard to the photoresistsolution, its temperature history beginning at its manufacturing time iscontinuously recorded (Block B12). In addition, even when the chemicalsolution is being utilized, its temperature history beginning at itsmanufacturing time is continuously recorded.

Then, the temperature history, of the photoresist solution, from themanufacturing to the connection of the chemical solution to the filmforming apparatus 2 and the predetermined calculation parametersdescribed above are inputted to the memory MR1 of the film formingapparatus 2 through the input device 22. Prior to the utilization of thephotoresist solution (Block B10), i.e., prior to film forming processing(Block B32), the calculating unit 14 of the film forming apparatus 2implements the calculation processing described above, based on thetemperature history data and the calculation parameters (Block B13).After receiving the calculated results, the determining unit 12determines that the determined performance of the chemical solution tobe used has desired properties (Block B16). In the case where thedetermined result is true, the procedure directly moves to the filmforming processing (Block B32). In contrast, if the determined result isfalse, after receiving the determined result, the warning-signalgenerating unit 16 of the film forming apparatus 2 generates and outputsa warning signal that urges the worker to replace the chemical solutionin a predetermined container or the chemical solution in a predeterminedzone (Block B34); the worker who has been indicated by an unillustrateddisplay or a warning sound to replace the chemical solution replaces thecontainer or the chemical solution in the zone (Block B36).

The change in the properties with time, of a chemical solution, isgenerally a function of temperature and time; however, it is believedthat the function form differs depending on the reaction mechanism ofthe chemical solution. As the simplest mechanism, a case is conceivablein which, even though the reaction coefficients of compositions, in thephotoresist solution, that cause the change with time have temperaturedependency, the density of reactive compositions hardly affects thereaction speed. In this case, considering the reaction coefficients upto first-order expansions, the amount of change in the compositions isin proportion to the quadrature by parts of temperature and elapsedtime. Accordingly, the determining that the properties of a chemicalsolution has the predetermined performance may be implemented, bysetting a threshold value for the quadrature by parts of temperature andelapsed time, and by utilizing the threshold value an a reference.

In the case where reaction coefficients are complex, by assuming a modelfunction for correlation data between the temperature and the elapsedtime, a threshold value for the model function can be set.

Moreover, in the case where a plurality of properties that deteriorateswith time exists, or in the case where the properties originate from aplurality of reaction mechanisms, the determination is implementedthrough logical multiplication of respective determinations. In thissituation, determinations that are not critical may be omitted.

Furthermore, properties that indirectly indicate the change in thephotoresist properties include the thickness of a film by apredetermined sequence of processing or viscosity, the average molecularweight of a photoresist resin (and the distribution of the molecularweight), or the amount of acid catalyzed functional groups. If thesephysical properties or chemical compositions can directly be measuredwith high accuracy and high reproducibility, and have correlations withthe photoresist properties, the results of measurement on these valuesthat indirectly indicate the photoresist properties may be added to thedata for the determination.

Some methods of recording the temperature history will illustrativelydescribed.

In the first place, a method will be discussed in which information onmeasurement results obtained through a plurality oftemperature-measurement devices is integrated. The specific examples ofthese types of information include: with regard to the duration from themanufacturing to the filling a chemical-solution container, atemperature specified in a management specification of the manufactureror the temperature history of a chemical-solution filling apparatus;with regard to the storage period of the chemical-solution container atthe manufacturer, the record of the temperature history of the storageplace or a temperature specified in the management specification; withregard to the duration of carriage from the chemical-solutionmanufacturer to the semiconductor-device manufacturer, the temperaturehistory of the carriage cabin of a carriage vehicle or a temperaturespecified in a management specification, if available; and with regardto the duration of storage in a warehouse of the semiconductor-devicemanufacturer, the temperature history of the inside of warehouse or atemperature specified in a management specification, if available. Afterthe loading of the chemical-solution container in the film formingapparatus, the temperature inside a clean room in which an exposureapparatus is stored, or the temperature specified in a managementspecification for the clean room, is utilized. With regard to thetemperature history up to the connection of the chemical-solutioncontainer to the film forming apparatus, the multiplication products oftemperature and time theretofore may directly be inputted through theinput device 22, and then the multiplication products of the temperaturehistory and the elapsed time, after the connection, may sequentially beadded.

As a further simple method, it is possible to utilize IC tags that haverecently been drawing attention in diverse industries.

As the first aspect of utilizing an IC tag, there is a method in which,every time a chemical-solution container with an IC tag changes itsstorage places, the multiplication products of the temperature historyand the storage time that have occurred during the duration from thelast move until the present move are added to the multiplicationproducts that are aggregated theretofore, or a method in which apredetermined calculation results are held.

As the second aspect of utilizing an IC tag, an IC tag is provided withat least a temperature measuring unit, such as a thermistor or a deviceutilizing the Seebeck effect, a recording unit, and a timer unit. Atemperature value measured every a constant duration that is specifiedby the timer unit, an integrated value of the measured temperaturevalues, a predetermined calculated value or an aggregated value ofpredetermined calculated values is stored in the recording unit. In thecase of the second aspect of utilizing an IC tag, the temperaturehistory of the chemical-solution container itself can be utilized;therefore, it is possible to implement with high accuracy thedetermination that the photoresist solution has desired performance forpredetermined properties.

According to the present embodiment, it is possible to accuratelyestimate the duration in which a chemical solution that deteriorateswith time demonstrates its desired properties. More particularly,effects to be obtained include two types; as far as the first effect isconcerned, by avoiding a case of utilizing a chemical solution whoseproperties has deteriorated, the quality of devices can be improved, andeventually, the yield rates of devices can be raised. As far as thesecond effect is concerned, even when a quality assurance period thatwas granted by the manufacturer has expired, successive utilization ispermitted if a chemical solution has desired properties; therefore, thecosts of chemical solutions and waste-solution disposal can be reduced.

The first effect described above will be discussed in more detail. If amanagement process whose temperature management is inappropriate existsduring the duration from the manufacturing of the chemical solution tothe forming of films by a film forming apparatus, a case occurs in whichthe chemical solution can not satisfy the determined properties eventhough its quality assurance period has not expired. For example,because of an accident of a delivery vehicle, or in a storage warehouse,in summer and the like, the storage temperature for the chemicalsolution may rise. Even in such a case, through the film formingapparatus 2 according to the present embodiment, by determining itfalse, based on the temperature history, that the chemical solution hasthe desired properties, or by disposing of a deteriorated chemicalsolution, deteriorated properties and poor properties of devices due tothe utilization of such a deteriorated chemical solution can beprevented, whereby the yield rate can be enhanced.

The second effect described above will be discussed in more detail. If amanufacturer of chemical solutions sets quality assurance periods, whileanticipating a certain extent of safety factors, the management based onthe quality assurance periods causes chemical solutions that can stilldemonstrate desired properties to be disposed of; therefore, thechemical solutions to be disposed of make the costs of chemicalsolutions and the cost of disposing of chemical solutions increase.According to the present embodiment, based on preliminarily obtaineddata, by utilizing the temperature history of a chemical solution, if itis determined to be true that the chemical solution has thepredetermined properties, the usable chemical solution can be usedcontinuously, whereby it is possible to reduce the cost. The secondeffect becomes particularly outstanding in the case where expensivechemical solutions are utilized.

(4) Embodiment 2

Next, Embodiment 2 of the present invention will be discussed, referringto FIG. 5.

In the present embodiment, unlike Embodiment 1 described above, thediscussion will be made by dealing with a case where a chemical solutionto be used is contained in a container that discharges the chemicalsolution by means of pressure-applying gas (e.g., nitrogen orbasic-substance-removed air).

The film forming apparatus 2 illustrated in FIG. 1 can be utilized alsoin the present embodiment. As a predetermined calculation that isimplemented by the calculating unit 14 and that is to describe thechange with time in the properties of a chemical solution, thecalculation utilizing the quadrature by parts of temperature and elapsedtime that has been utilized in Embodiment 1, as the simplest method, isemployed.

In the case of a chemical-solution bottle conceived in Embodiment 2, aphotoresist solution deteriorates its performance, depending on theelapsed time during which the bottle is being loaded in the film formingapparatus and the photoresist solution is being contacting with thepressure-applying gas. The resolution limit is a typical example ofperformance that deteriorates. In this case, it is preferable todetermine that the photoresist has predetermined performance forpredetermine properties, while taking into consideration a duration fromthe loading as well.

In Embodiment 2, by obtaining the data (e.g., the data corresponds tocorrelation data) for acquiring a relationship between the temperatureand the time (e.g., the temperature and the time correspond to datarelated to the properties of a chemical solution) during which thephotoresist solution is being contacting with the pressure-applying gas,and the photoresist-performance deterioration caused by theabove-mentioned temperature and the time, a threshold value for theaggregate sum of the products of the chemical-solution temperature andthe elapsed time is calculated, as is the case with Embodiment 1 (BlocksB22, B24 and B26 in FIG. 5).

The calculating unit 14 of the film forming apparatus 2 calculates theaggregate sum of the products of the chemical-solution containertemperature and the elapsed time, after the loading; the determiningunit 12 compares the aggregate sum with the threshold value to implementa determination. The criteria are the same as those in Embodiment 1.

However, in Embodiment 2, by dealing with a case, as a typical example,where the storage at a chemical-solution manufacturer or a devicemanufacturer is implemented at a high temperature or for a long time, orat a high temperature and for a long time, the temperature history fromthe manufacturing of a chemical solution may be considered according tothe same method as that in Embodiment 1 described above. In Embodiment2, the determination is implemented by utilizing the logicalmultiplication (LC2) of the determination on the value calculated byutilizing the temperature history from the manufacturing of a chemicalsolution (Block B16), and the determination on the value calculated byutilizing the temperature history from the loading of achemical-solution container (Block B26). In other words, when the twodeterminations are true, the determination in Embodiment 2 is true.

(5) Embodiment 3

Next, Embodiment 3 of the present invention will be discussed, referringto FIGS. 6 and 7.

FIG. 6 is a block diagram illustrating the schematic configuration of afilm forming apparatus according to Embodiment 3. As is clear from thecomparison to FIG. 1, a film forming apparatus 4 illustrated in FIG. 6is provided with a chemical-solution disposal commander 18, in additionto the configuration in FIG. 1. The rest of the configuration of thefilm forming apparatus 4 is substantially the same as that of the filmforming apparatus 2 of Embodiment 1.

In the film forming apparatus 4 illustrated in FIG. 6, if the result ofa determination by the determining unit 12 is false, thechemical-solution disposal commander 18 creates a disposal commandsignal and sends it to an unillustrated valve opening/closing device; inconsequence, the chemical solution remaining within the path from thechemical-solution outlet (refer to FIG. 8) of a chemical-solutioncontainer to the discharging nozzle NZ (refer to FIG. 8) for a substrateis automatically disposed of (Block B42 in FIG. 7).

In Embodiment 3, it is necessary to appropriately figure out the volumeof the chemical solution remaining in each of pipelines, in respectivezones, that are provided in the film forming apparatus 4.

In disposing of a chemical solution, as Embodiments 1 and 2 describedabove, by issuing an indication that urges the replacement of achemical-solution container, concurrently with a disposal command

(Block B34), the disposal of remaining chemical solution may becontrolled after the replacement of the chemical-solution container(Block B36).

According to Embodiment 3, by determining that chemical solutionssituated in respective portions within a pipeline have predeterminedproperties, if the determination turns out to be false, it is possibleto more accurately calculate the amount of a chemical solution to bedisposed of. Accordingly, not only a chemical solution whose performancehas deteriorated can be prevented from being continually utilized bymistake, but also the cost of treating the waste solutions can bereduced; furthermore, the amount of a replaced chemical solution that ismade to flow in a pipeline is reduced, thereby enabling the cost ofchemical solution to be reduced.

(6) Embodiment 4

Embodiment 4 is characterized by that, in a semiconductor productionline that is equipped with a plurality of film forming apparatuses, byanticipating the temperature history up to the scheduled processing timeinstant of a production lot (Lot) to be processed by a film formingapparatus on which attention is focused, and by preliminarilydetermining that a needed chemical solution has its desired properties,unevenness in device properties is suppressed.

A typical semiconductor production line is provided with an upper-layermanufacturing management system that is informatively coupled toapparatuses in the production line; the scheduled arrival time instantsof lots to be processed with respective film forming apparatuses aretransmitted from the manufacturing management system to the respectivelower-layer film forming apparatuses. In such a film forming apparatus,with regard to a chemical solution required to process a production loton which attention is focused, the temperature history of thechemical-solution container during the duration from the time point ofimplementing determination processing to the scheduled time instant ofstarting processing of the production lot is anticipated. After that, inthe same manner as that described above in Embodiment 1 or Embodiment 2,by utilizing at least one of two pairs, i.e., the elapsed time from themanufacturing of a chemical solution and the temperature historyincluding the foregoing anticipation, at the scheduled time instant ofprocessing the production lot, and the elapsed time from the loading ofa chemical-solution container to the film forming apparatus and thetemperature history including the foregoing anticipation, at thescheduled time instant of processing the production lot, thedetermination that the chemical solution has desired performance forpredetermined properties is implemented. The film forming apparatus isprovided with a mechanism in which, if the foregoing determination isfalse, a signal that urges the worker to replace the chemical solutionwithin the pipeline in the related zone is issued, and the chemicalsolution within the pipeline in the zone is automatically disposed of.

In consequence, by disposing of the chemical solution on which the falsedetermination was implemented with regard to the foregoing properties,it is possible to prevent deteriorated chemical solutions from beingutilized. Moreover, in Embodiment 4, the chemical solution is replacedbefore the production lot is delivered to the film forming apparatus, inparticular, not immediately before the processing of wafers, but whileensuring some extent of time margin; therefore, it can be preventedthat, due to a pause of the film forming apparatus while a chemicalsolution whose properties have deteriorated is replaced, waiting timeoccurs. Still moreover, by implementing the foregoing determination foreach production lot, disposal processing can be carried out betweenproduction lots; therefore, change in film forming properties betweenproduction lots, and eventually, instability of device properties, dueto the replacement of the chemical solution while the processing of aplurality of substrates that configures each production lot, can besuppressed.

As methods of anticipating the temperature history up to the processingof a lot, for example, the following two approaches are conceivable:

1) A method of extrapolating a temperature history up to thedetermination starting time point

2) A method of employing as a specified value the management referencetemperature of a clean room in which a film forming apparatus on whichattention is focused operates

It goes without saying that other methods than those listed above can beemployed, if they are appropriate.

(7) Embodiment 5

Next, Embodiment 5 of the present invention will be discussed, referringto FIGS. 6, 8, and 9.

Embodiment 5 is characterized by being configured in such a way that, inthe film forming apparatus 4 illustrated in FIG. 6, the determining unit12 implements the determination, for each section of a pipeline throughwhich a chemical solution passes, that the chemical solution has desiredproperties, and that, if there is a section for which the result of thedetermination is false, by a command signal from the chemical-solutiondisposal commander 18, the chemical solution of an amount thatapproximately corresponds to the pipeline capacity from the section withdetermination result of being false to the front edge of a nozzle isautomatically disposed of.

FIG. 8 illustrates the principal parts of a film forming apparatus 5according to Embodiment 5. In drain tanks DT2 and DT4 and in a filter F,unillustrated valve opening/closing devices are provided; in the casewhere a command signal is issued from the chemical-solution disposalcommander 18 (refer to FIG. 6), each valve is opened, and then thechemical solution remaining in the pipeline is disposed of. In addition,the result of the determination by the determining unit 12 (refer toFIG. 6) of the film forming apparatus 5 is true, as indicated by anarrow AR in FIG. 8, the pipeline P10 is carried in such a way that thedischarging nozzle NZ is situated above a wafer W, and then the chemicalsolution is applied onto the wafer W.

In Embodiment 5, because chemical solutions to be utilized are liquid,even the chemical solutions in the adjacent location within a pipelineinclude mixed chemical solutions whose temperature histories aredifferent in a strict sense. Accordingly, as methods based on assumptionof the mixture of chemical solutions, for example, the following twomethods are conceivable.

1) In the determination, taking into consideration distances from thechemical-solution container, the disposal of each chemical solution isimplemented on the basis of a certain volume or a certain proportion ofvolume, or a certain volume and a certain proportion of volume, of eachchemical solution, within the capacity of the pipeline from the placewhere the determination is false to the front edge of the nozzle.

2) By assuming that there is the mixture of chemical solutions within acertain distance from the determination place on which attention isfocused, and by implementing the determination on the chemical solutionin the place that is the most disadvantageous to the determination (ineffect, in a predetermined place that is closer to the front edge of thenozzle than the place on which attention is focused is), the disposal ofchemical solutions within the capacity of the pipeline from the placethat is the determination place, or that is closer to thechemical-solution container by the certain distance than thedetermination place is, to the front edge of the nozzle is implemented(Block B46 in FIG. 9).

According to Embodiment 5, the amount of chemical solutions to bedisposed of can be reduced more than the amount in the case ofEmbodiment 4 described above.

(8) Embodiment 6

In a semiconductor production line in which the upper-layermanufacturing management system that has been dealt with in Embodiment4, when production-lot processing is allocated to the foregoingplurality of film forming apparatuses, the production lot in which theforegoing chemical solution on which attention is focused ispreferentially allocated to the system in which a chemical solution isloaded that has the smallest margin between a predetermined thresholdvalue and the result of a predetermined calculation based on thetemperature history and the elapsed time from the manufacturing date orthe elapsed time from loading in a system, of a chemical solution thatis utilized for the foregoing film forming on which attention isfocused, or based on the temperature history, and the elapsed time fromthe manufacturing date and the elapsed time from loading in a system. Inconsequence, the amount of chemical-solutions to be disposed of in allof the plurality of film forming apparatuses can be further reduced.

(9) Embodiment 7

FIG. 10 is a block diagram for explaining Embodiment 7 of the presentinvention. FIG. 7 shows a film forming apparatus comprising amanufacturing management system 7 as an upper system and film formingapparatuses FF1 to FFN (N is a natural number), as a lower system,connected to the manufacturing management system 7.

The film forming apparatuses FF1 to FFN comprise respective detectorsDR1 to DRN that each measures the temperature of a chemical solution tobe loaded and applied pressure, if necessary, and supply themanufacturing management system 7 with the measurement results alongwith information on elapsed time.

The manufacturing management system 7 comprises an interface 34 thatenables the information transfer between the manufacturing managementsystem 7 and the film forming apparatuses FF1 to FFN, the memory MR1,the calculating unit 14, the determining unit 12, the chemical-solutiondisposal commander 18, and a display 32 that displays the result ofdetermination by the determining unit 12. The chemical-solution disposalcommander 18 according to Embodiment 7 corresponds to, for example,commanding means. The manufacturing management system 7 calculates inthe same way as those described above in Embodiments 1 and 2 thetemperature history or the pressure history of a chemical solution,based on measurement values supplied by each of the film formingapparatuses FF1 to FFN, determines that the chemical solution loaded ineach film forming apparatus has its expected quality, for each apparatusand for each section of the pipeline that each apparatus possesses, anddisplays the determination results on the display 32. In addition,according to the results of determination by the determining unit 12,the chemical-solution disposal commander 18 of the manufacturingmanagement system 7 creates for each film forming apparatus and for eachsection of the pipeline of each apparatus a signal commanding that thechemical solution in which section of the pipeline of which apparatusshould be replaced, and supplies each of the film forming apparatusesFF1 to FFN with that signal. The film forming apparatus that hasreceived the signal implements the disposal and the replacement of thechemical solution, according to the command from the chemical-solutiondisposal commander 18.

According to Embodiment 7, the utilization of a chemical solution whosequality and performance has deteriorated can accurately andsystematically be prevented, while the continual utilization of achemical solution that is usable can systematically be realized;therefore, a film forming apparatus that can form films at a high yieldrate and at a low production cost is provided.

(10) Manufacturing Method of Semiconductor Device

The manufacturing of semiconductor devices by utilizing the film formingmethod that comprises a series of processing procedures described aboveenables the semiconductor devices to be manufactured at a high yieldrate and at a low production cost.

Some embodiments of the present invention have been discussedheretofore; the present invention is by no means limited to theforegoing embodiments, and it is obvious that various modifications ofthe present invention can be implemented within the technical scopethereof. For example, in the foregoing embodiments, cases where thepresent invention is applied to semiconductor devices have beendiscussed; however, devices to which the present invention is appliedare by no means limited to semiconductor devices, and the presentinvention can also be applied to liquid crystal devices, dielectricdevices, optical devices, and organic devices that involve the formationof films during the manufacturing thereof. Moreover, types of chemicalsolutions are not limited to photoresist films and SOG films describedabove; it goes without saying that the present invention can also beapplied, for example, to general film-forming-type antireflection films,interlayer insulation films, color filter materials, and the like. Forexample, in film-forming-type antireflection films, properties thatdeteriorate with time include a complex refractive index (orantireflective performance corresponding to the complex refractiveindex), the number of defects in film-forming, the density of acidsubstances in a film (or photoresist deformation corresponding to thedensity of acid substances in a film), an etching speed (pattern-shapedeformation corresponding to the etching speed), and the like. Ininterlayer insulation films, properties that deteriorate with time arevalues related to electric insulation, such as a dielectric constant andfilm density.

In addition, the determination has been implemented on the basis ofwhether the proposition that a chemical solution has its desiredproperties with regard to specific properties is true; however, aprocess of determination may be employed which involves determinationformulas and processes substantially equivalent, e.g. contraposition.

1. A film forming apparatus which forms a film on a substrate byutilizing a chemical solution, comprising: a correlation data creatingunit which creates a correlation data that is related to the quality ofa chemical solution, from data that is related to the properties of thechemical solution including at least one of data on storage temperaturefor the chemical solution to be loaded and data on pressure applied tothe chemical solution to be loaded; and a determining unit whichdetermines whether or not the chemical solution holds expected qualitythereof on the bases of the correlation data.
 2. A method ofmanufacturing semiconductor devices, comprising a method of forming afilm on a substrate, said method of forming a film including: creating acorrelation data that is related to the quality of a chemical solutionfrom data that is related to the properties of the chemical solutionincluding at least one of data on storage temperature for the chemicalsolution to be loaded and data on pressure applied to the chemicalsolution to be loaded; and determining whether or not the chemicalsolution holds expected quality thereof on the bases of the correlationdata.
 3. The film forming apparatus according to claim 1, wherein thedata that is related to the properties of the chemical solution includestemperature history data that represents a history of the storagetemperature from an arbitrary time point to a time point when thechemical solution is utilized.
 4. The film forming apparatus accordingto claim 3, wherein the arbitrary time point is a time point when thechemical solution is loaded.
 5. The film forming apparatus according toclaim 1, wherein the data that is related to the properties of thechemical solution further includes data during a time in which thepressure is applied to the chemical solution.
 6. The film formingapparatus according to claim 1, which further comprises a pipeline thatleads the chemical solution to the substrate, wherein the correlationdata is created for arbitrary places within the pipeline, and whereinthe determining unit determines for each of the arbitrary places whetheror not the chemical solution holds the expected quality.
 7. The filmforming apparatus according to claim 1, which further comprises apipeline that leads the chemical solution to the substrate and that canbe divided into a plurality of sections, wherein the correlation data iscreated for each of the sections, and wherein the determining unitdetermines for each of the sections whether or not the chemical solutionholds the expected quality.
 8. The film forming apparatus according toclaim 1, wherein the chemical solution is utilized at a specific timepoint in the future and wherein the determining unit predictivelydetermines whether or not the chemical solution holds the expectedquality at a specific time point in the future.
 9. The film formingapparatus according to claim 1, which further comprises a warning-signalgenerating unit which creates a warning signal that urges replacement ofthe chemical solution in response to the determination of thedetermining unit.
 10. The film forming apparatus according to claim 1,which further comprises a chemical-solution disposal commander thatmakes the chemical solution be disposed of, in response to thedetermination of the determining unit.
 11. A manufacturing managementsystem which allocates product lots to a plurality of external filmforming apparatuses which forms films on substrates by utilizingchemical solutions, said film forming apparatuses each comprising acorrelation data creating unit which creates correlation data that isrelated to the quality of a chemical solution from data that is relatedto the properties of the chemical solution including at least one ofdata on storage temperature for the chemical solution to be loadedtherein and data on pressure applied to the chemical solution to beloaded therein, and a determining unit which determines on the basis ofthe correlation data whether or not the chemical solution holds expectedquality thereof; said manufacturing management system determines foreach of the external film forming apparatuses a margin of the chemicalsolution for the expected quality, based on a result of determination bythe determining unit of the external film forming apparatus exteriorthereto, and then decides priorities among the film forming apparatuses,based on the results of determination on the margins; and wherein theallocation is implemented by the decided priorities.
 12. Themanufacturing management system according to claim 11, wherein the datathat is related to the properties of the chemical solution includestemperature history data that represents a history of the storagetemperature from an arbitrary time point to a time point when thechemical solution is utilized.
 13. The manufacturing management systemaccording to claim 12, wherein the arbitrary time point is a time pointwhen the chemical solution is loaded.
 14. The manufacturing managementsystem according to claim 11, wherein the data that is related to theproperties of the chemical solution further includes data during a timein which the pressure is applied to the chemical solution.
 15. Themanufacturing management system according to claim 11, wherein thechemical solution is utilized at a specific time point in the future andwherein the determining unit that is comprised in the film formingapparatus predictively determines whether or not the chemical solutionholds the expected quality at a specific time point in the future.
 16. Amanufacturing management system connectable to a plurality of externalfilm forming apparatuses which forms films on substrates by utilizingchemical solutions, said film forming apparatuses each comprising acorrelation data creating unit which creates correlation data that isrelated to the quality of a chemical solution from data that is relatedto the properties of the chemical solution including at least one ofdata on storage temperature for the chemical solution to be loadedtherein and data on pressure applied to the chemical solution to beloaded therein, and a determining unit which determines whether or notthe chemical solution holds expected quality thereof on the basis of thecorrelation data; said manufacturing management system determining foreach of the film forming apparatuses a margin of the chemical solutionfor the expected quality on the basis of a result of determination bythe determining unit of said film forming apparatus, deciding prioritiesamong the film forming apparatuses on the basis of the results ofdetermination on the margins, and allocating respective product lots tothe film forming apparatuses based on the decided priorities.
 17. Amanufacturing management system connectable to an external film formingapparatus which forms a film on a substrate by utilizing a chemicalsolution, said film forming apparatus comprising a detecting unit whichdetects correlation data that is related to the quality of a chemicalsolution from data that is related to the properties of the chemicalsolution including at least one of data on storage temperature for thechemical solution to be loaded therein and data on pressure applied tothe chemical solution to be loaded therein, said manufacturingmanagement system comprising a determining unit which determines whetheror not the chemical solution holds expected quality thereof on the basisof the correlation data received from said external film formingapparatus, and a commanding unit which creates a signal to urgereplacement of the chemical solution in response to determination of thedetermining unit to supply the external film forming apparatus with thesignal.
 18. The manufacturing management system according to claim 17,wherein the data that is related to the properties of the chemicalsolution includes temperature history data that represents a history ofthe storage temperature from an arbitrary time point to a time pointwhen the chemical solution is utilized.
 19. The manufacturing managementsystem according to claim 18, wherein the arbitrary time point is a timepoint when the chemical solution is loaded.
 20. The manufacturingmanagement system according to claim 17, wherein the data that isrelated to the properties of the chemical solution further includes dataduring a time in which the pressure is applied to the chemical solution.